| 摘要 |
PURPOSE:To avoid the break of electrode wires when a reverse conductive type region is provided in a part of a one conductive type semiconductor substrate and a diffused region is formed in a respective region, by alternately providing masks, selectively performing diffusion, and reducing the difference in steps in an oxide film covering said region. CONSTITUTION:A P<-> type region is diffused and formed at the peripheral part of the N<-> type Si substrate, and a thick oxide film 1 is deposited on the entire surface including said region. The film 1 at a transistor forming region is removed, and a thin gate electrode 2 is deposited on the entire surface. Then a polycrystal Si film is grown on the entire surface, source and drain regions are removed, a lower film 2 is removed with the remaining polycrystal Si film as a mask, and the Si surface is exposed. Then a new polycrystal Si film 3' is grown on the entire surface, the film is coated with a CVD oxide film 4, a part of it is removed, P<+> diffusion is performed from the top of the film 3', and a P<+> type region holding the gate oxide film 2 is formed in the N<-> type substrate. Then the region is coated by a CVD oxide film 5, the film 4 is removed, and an N<+> region holding a gate oxide film 2 is provided in the P<-> region. |
